Art journaling was my passion just before diving into Bible journaling (or journaling in my Bible). While learning about art journaling and all the sorts of mediums, I began using lots of matte decoupage and matte gel medium to glue and seal my projects and pages. They are, both, wonderful products. The gel is just more thick than the decoupage.
Well, I got to wondering....could I actually use decoupage as a sealer for my Bible pages. So I took the risk and tried it on the very first page of scripture in the Bible, Genesis 1! I applied a thin layer of my favorite matte decoupage, Aleen's, to the entire page and dried it with my heat gun. When I do this, I always put a piece of parchment paper under the page to prevent the next page from gluing to the page I am sealing. Then, I colored around the edges with some up & up watercolor gel crayons and Crayola Twistable Slick Sticks. These work much like gelatos and are much more affordable. They just aren't as high of a quality and don't come in the variety of colors. This part of the process takes more experimentation and is just a matter of artist interpretation. I really like the gold Slick Stick color because you can add just a couple scribbles of it and it will add a slight shimmer to the area where you "paint" it.
After drying with the heat gun I added some number stickers from Mambi to label each of the days of the Creation. The pages is still a little crumpled looking, but it will smooth out a little while the pages are closed and under the weight of the Bible itself. It's a simple page, but I like it. Trust your instincts and try something new!